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e Aik UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

Region 1

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5 Post Office Square Suite 100

7t pFlc Boston MA 021093912

May 16 2013

Patricia W Aho Commissioner

Maine Department of Environmental Protection

17 State House Station

Augusta ME 043330017

Re Review and Action on Water Quality Standards Revisions

Dear Commissioner Aho

By letter of January 14 2013 the Maine Department of Environmental Protection

DEP submitted revisions of the States surface water quality standards to Region 1 of

the United States Environmental Protection Agency EPA orRegion for review

The revisions were adopted by the DEP on July 13 2012 By letter to EPA dated January

9 2013 Maines Assistant Attorney General in the Natural Resources Division certified

the revisions as having been duly adopted pursuant to state law The Region has

completed its review of the submitted revisions to the arsenic criteria as further described

below

Pursuant to Section 303c2 of the Clean Water Act and 40 CFR Part 131 I hereby

approve the following water quality standards revisions to 38 MRSA §420 sub §2 as set

forth inPL 2011 Ch 194 LD 515 An Act To Review State Water Quality Standards

and CMR 584 Surface Water Quality Criteriafor Toxic Pollutants

I Revision of the cancer risk level used to calculate the human health criteria for

arsenic from one in 1000000 to one in 10000 and

2 Revision of the arsenic criteria to protect human health from 0012 to 13 iteL

for the consumption of water and organisms and from 0028 to 37 pgL for

the consumption of organisms only

We are still reviewing revisions to the acrolein and phenol criteria and are not taking

action on those revisions at this time

EPA acknowledges your request to approve the revisions for all waters including waters

that are within Indian territories Todays approval does not extend to waters that are

within Indian territories EPA intends to publish a notice explicitly seeking public input

on the applicability of the revised arsenic criterion in question to waters within Indian

territories before completing its review Therefore EPA is taking no action to approve or

disapprove the States revisions with respect to those waters at this time In the

meantime EPA will retain responsibility under Sections 303c and 303d of the Clean

Water Act for those waters

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Discussion

In implementing LD 515 DEP reviewed the available scientific literature on the factors

that are used to derive water quality criteria to protect human health uses including

fishing recreation in and on the water and where applicable drinking water DEP also

reviewed data specific to waters in Maine and used the information to derive arsenic

criteria for Maines waters

Arsenic is a known carcinogen that may cause cancer in skin or internal organs such as

the liver lungs and bladder1 In its 304a criteria recommendations EPA states that

arsenic criteria should be applied as inorganic arsenic2 As is the case for all pollutants

EPAs 2000 Human Health Methodology encourages states to use local and regional data

when making risk management decisions inherent in developing criteria including

decisions inherent in selecting the appropriate fish consumption rate target risk level and

bioaccumulation factor3

Maines revised numeric criteria for arsenic were derived using the same general

methodology and equations used to calculate EPAs current 304a recommended criteria

for carcinogens The revised criteria and the input variables used to calculate the criteria

are summarized in Table 1 below The paragraphs that follow explain those components

of the calculation that have been revised to form the basis of Maines new arsenic criteria

Cancer Risk Factor RV The State of Maine enacted LD 515 in 2011 directing DEP to

revise Maines human health water quality criteria for arsenic based on a cancer risk

factor of 1 in 10000 rather than the previous RF of in 1000000 EPAs recommended

methodology for the derivation of water quality criteria states that 1 in 1000000 or 1 in

100000 may be acceptable cancer risk factors for the general population and that highly

exposed populations should not exceed a 1 in 10000 risk leve14

Fish Consumption Rate FCR Maines previous 324 gday FCR represents the 94th

percentile for Native American anglers in Maine and the 95th percentile for the total

angler population in Maine based on data from a 1990 survey of licensed Maine anglers5

In deriving the new arsenic criteria DEP used 138 gday which is the 99th percentile of

this survey to ensure that the criteria are protective of subsistence fishers a highly

exposed population This approach is consistent with EPA recommendations for

Agency for Toxic Substances and Disease Registry ATSDR Toxicological Profile for Arsenic Atlanta

Georgia August 2007 Available at httpwwwatsdrcdcgovsubstancestoxsubstanceasptoxid=3

2

EPA National Recommended Water Quality Criteria human health criteria for arsenic published 1992

available at httpwaterepagovscitechswguidancestandardscriteriacurrentindexcfm

3

84 EPA 2000 Methodology for Deriving Ambient Water Quality Criteriafor the Protection of Human

Health US Environmental Protection Agency Office of Water Washington DC EPA 822B00004

page 26 Available at httpwwwepaeovwaterscienceeriteriahumanhealthlmethodcompletepdf

4

EPA 2000 Methodology for Deriving Ambient Water Quality Criteriafor the Protection of Human

Health US Environmental Protection Agency Office of Water Washington DC EPA822B00004

page 26 Available at httpwwwepagovwaterscienceicriteriatumanhealthimethodcompletepdf

5

Ebert ES RE Keenan JW Knight and NW Harrington Consumption of Freshwater Fish by Maine

Anglers proceedings of the 1992 TAPPI Environmental Conference

2

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Table 1 Comparison of Maines Previous and Revised Arsenic Criteria

Parameter 2005 criteria 2012 criteria

Cancer Risk Factor RE 1 x 106 lx 104

Body Weight BW 70 kg 70 kg

Cancer Potency Factor q1 175 mgkgday 175 mgkgday

Water Consumption DW 2 Lday 2 Lday

Bioconcentration Factor BCF 44 Lkg 26 Lkg

Fish Consumption Rate FCR 324 gday 138 gday

Inorganic Factor IF none6 30

Criteria to protect human health for consuming

fish and drinking water water + organism

=1000 x RF x BW

ql x DW + BCF x FCR x IF

0012 ugL 13 tie

Criteria to protect human health for consuming

fish only

=1000x RF x BW

1 x BCF x FCR x IF

0028ggL 37 pgL

estimating fish consumption rates for subsistence fishers and is appropriate to ensure that

highly exposed subpopulations are not exposed to a risk level greater than 1 in 10000

Inorganic Factor IF Arsenic is present in the environment and in fish tissue in both

organic and inorganic forms Inorganic arsenic is the form that is most toxic to humans

and used to develop toxicity data for cancer and other end points The IF is the ratio of

inorganic arsenic to total arsenic in fish tissue DEP conducted its own literature search

which found a range of observed IF values from 10 to 30 According to DEPs review

the lower end of this range is based on average results whereas maximum amounts are

observed to approach or exceed the upper end of the range depending on species and

other factors DEP chose the more protective end of this range7

Bioconcentration Factor BCF Bioconcentration refers to the uptake and retention of a

chemical by an aquatic organism from water The BCF is the ratio of the concentration of

a substance in the tissue of an aquatic organism to its concentration in the ambient water

in situations where the organism is exposed through the water only and the ratio does not

6

The 2005 criteria did not include adjustment to the criteria based on an assumption of a ratio of inorganic

to total arsenic Therefore IF was not included in the 2005 calculation Instead DEP assumed a ratio of

50 inorganic arsenic to total arsenic in developing water quality based effluent limits for dischargers

subject to licensing under Maines National Pollution Discharge Elimination System EPA understands

that with the adoption of the new arsenic criteria DEP will no longer make those adjustments

See 1272011 email from Robert D Stratton DEP to Ellen Weitzler and Stephen Silva EPA

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change substantially over time Maine has updated the BCF used for the arsenic criteria

based on a 2011 BCF derivation for arsenic conducted by EPA in support of an arsenic

criteria revision in Oregona The 2011 derivation used a larger set of studies than were

available in 1980 when the 44kgL BCF used in the 2005 Maine arsenic criteria was

developed

EPA approves of the WQS revision to the arsenic criteria on the basis of the

demonstrated use of available sound science including state specific data to derive the

new criteria

We look forward to continued cooperation with Maine in the development review and

approval of water quality standards pursuant to our responsibilities under the Clean Water

Act Please contact Ellen Weitzler 6179181582 if you have any questions

Sincerely

Kenneth Moraff Acting Director

Office of Ecosystem Protection

cc Brian Kavanah MEDEP

Tracy Bone EPA SSB

Jennie Bridge EPA

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EPA Region ICI Technical Support Document for Action on the State ofOregons New and Revised

Human Health Water Quality Criteriafor Toxics and Associated Implementation Provisions Submitted July

12 and 21 2011 October 17 2011

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